SAW Based Tube Rotation with Wireless Power Transfer

During last two years it was found both experimentally and theoretically that a cylindrical piezoelectric tube with a symmetric polarization perpendicular to its surface can be rotated due to the excitation of counter-propagating surface acoustic waves (SAWs) with different amplitudes. The excitation of the waves has been realized by a ring unidirectional transducer (RUDT) placed along the tube surface. This leads to the appearance of a permanent torque that rotates the tube as a whole. Such a structure can be considered as a motor without any stator. But in practice the presence of a thread of suspension for the tube and as well as electrical wires contacting the RUDT strongly hinder and limit the rotation effect. The objective of this work is to consider a wireless power transfer (WPT) system in order to enhance the rotation effect of the piezoelectric tube.